Centering clamp for pipe-working tools



Feb. 5, 1929. 1,701,281

v. T. saaAeug OHNTERING CLAMP FOR PIPE WORKING TOOLS Filad/Feb. 29, 1?28 2 sheets-5:16am 1 gwventoa Qu et MW Feb.5,1929. V 1,701,281

' V. T. SPRAGUE CBN'I'ERING CLAMP FOR PIPE WORKING TOOLS Filed Feb. 29. 1928 2 Sh69t$-5h66t 2- a f M i 5 z Ei 2o 5 6 Z Z E 5 Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

VERNON T. SPBA GUE, OF WARREN, OHIO, ASSIGNOR TO THE BORDEN COMPANY, OF

WARREN, OHIO, A CORPORATION OF OHIO.

' onn'rnnnve GLAMP r03 PIPE-WORKING TOOLS.

Application filed February 29, 1928. Serial No. 257,886.

This inventionrelates to means for centrally-clamping about a pipe,.the stationary portion of a pipe working tool, as for instance a die stock. The rimary object of the invention is to provi e a clamping device which will very firmly hold the'stationary annular frame to the pipe.

My clampis well adapted for that type of die stock, suitable for comparatively large pipes, where a driving mechanism is mounted on the clamp and accordinglyfthe rotative thrust is taken by. the stationary frame, and thus there is considerable stress on the clamp tendingto turn it about the pipe. To the above end, I provide sets of radial abutment members carried. by. the.

stationary frame and suitable screw mechanism for simultaneously forcing the mem-.

bers of a set toward the pipe. This enables me to obtain a very effective clamping.

Furthermore, I provide indications on the abutment members to designate the different sizes ofv pipe for which they maybe positioned, andthus each set may be accurately located to cause the pipe to be centered.

A preferred embodiment of my invention is illustrated in the drawings in conjunction with a. die stock having a driving member mounted on the stationary frame; V v

Fig. 1 is a sectional side elevation of such clamp and die stock;"Fig. 2 is an end elevation of the same looking from the right hand'end, and showing the clamp engaging the smallest pipe for which the device is adapted; 3 is a similarview' showing the clamp engaging the largest size pipe within the range of the machine; Fig. 4 is a fragmentary View of one of the sets of abutment members looking radially inward at the head thereof; Fig. 5 is a cross-section through the same, as indicated by the line 55 on Fig. 3; Fig. 6 is a sectional side elevation of one of the abutment members'detached. l

"In the drawings, 10 indicates the annular stationary frame which may surround pipes of'varlous sizes, as the small size pipe A in- Figs. 1 and2, or the large i ip 1 Fig. '3. This frame has a cylindrical portion of material length on the outer surface mg a pair of cylindrical holes through the frame ring. Each plunger is formed with a lateral recess 21 near its outer end and a head flange22 slightly overhanging the base of the recess. The two recesses in each clamping-unit shown face each other and are occupied by a disk 30. Passing through this disk isa clamping screw 40, which is threaded into the boss and ring 11, 10 and has an angular head overhanging the disk.

It. results from the above "construction that if the screw 40 is turned in, the two 'plungers 20 are correspondingly forced radially inwardly. the head of the screw engages the cross-head disk 30 for a considerable area and the disk engages the plungers 20 for a considerable area so that a very effective inward forcing action is obtained.

A reverse movement of the screw 40 .re'

In this forcing action lieves the pressure on the plungers 20 and.

either carries them outwardly or allows them to be moved outwardly, in either case releasing the pipe. If the disk 30'is internally threaded and screwed on the shank of the screw30 tightly against the head, so as to rotate it as a unit with the screw,

then the .outward turning of the screw On the carries the plungers 20 with it. other hand if the disk 30 has simply a cylindricalhole in it, so that the screw shank passes freely through it, the turning out of the screw does not of itself retract the plungers but enables them'to be shoved out by hand.

As the'three clamping units areset independently by turning in the corresponding screws 40, it is desirable that they be marked to indicate their position; Accordingly, I form graduations on the plungers, or at least on that one which visible from the adjacent exposed end of the clamp, which graduations coact with the outer surface of the boss llto indicate the position,

As will be noticed from Fig. 5, the notches in the plungers 20 may have straightouter walls,- which enable such notches tov be conveniently DlilClllllGCl, and alsowp1e-= vents any undue binding of the crosshead disk. At the same time the plungers cannot turn on their own axis sufficiently to remove the size-marking from-a veryvis'ibl'e position. plungers above the crosshead is'nconsiderablyless than the portion of theplunger be neath' the' crosshead, thus allowing plenty of room forthe head'of the screw 40. At the same time thisoverh'ang is suffi-cienit'to enablt-lfecrosshead if moved outwardly. to

pull out the corresponding plungers.

The stationary frame 10 may carry the die stock or other. pipe Working tool in any suitable-'manner. Asshownxit has a cup like extension 15 formediwith an outward flange 161' The: die stock frame, indicated at 50", abuts' this flange and has secured to-it' aring 51 overhanging the frame flange,

wlrerebythedi'e stock frame is rotatably.

mounted on the stationary frame 10.

In Fig. 1, I have shown the die stock frame as having. a cylindrical portion 53extendingwithin the cup of the stationary framdandterminating in'a'bevel gear 54.. This gear meshes withv a bevel pinion 60.

mou-nted on'the inner end ofia' drive shaft 61wh ich is journalled in a radialb'earing.

orr'the'stationary frame. As shown, this ClllVG' SllilftlS ournalled in asleeve which is screw threaded;or otherwise secured, to

an approximately cylindrical boss 18 formed on thestatiOnary frame 10.

With the mechanism above described, when thestationary frame is clamped on the pipe, a crank applied to the squared outer end 62 of'the drive shaft may rotate the pinion 60 and thus'powerfully rotate the die stock head and cut or thread th'e pipe by and adapted to engage a pipe surrounded. by v the frame, each clamping unit comprising a' plurality of longitudinally aligned in- The overhanging flange 22 of the wardly movable members and a forcing device to move said members inwardly simultaneously.

2. In a centering clamp, the combination of an annular frame, a plurality of clampbig unit-s mounted therein and adpated to engage a pipe surrounded by the frame,

each unit comprising a plurality. of' longitudinally aligned slidable plungers, and mechanism for operating neously'.

3. In"aicenteringyclamp, the combination of an annular frame, a plurality of clamping units-spaced about the frame and operatthem simulta- 7 ing radially toward the axis thereof, each unit comprisii'ig a" pair of radially movable plungers in longitudinal alignment and means independent for. each" pair 'forforc in'gboth members of the pair inward simul taneously. V I I 4. I a' centering clamp forzpipe working; tools, the combination of an annular. frame adapted *tosurroundfa pipe, and a clamping, unit slidably mounted in the frame and comprisin a plurality of movableplungers, a

crosshead' engaging; such plurality ofi plungers,and screw means for moving the crosshead.

5. In a. pipe workin'gtool, jthe combination of an annular frame, a pair of longitndinally alignediplungers mounted radially, therein, a screw threaddih' the frame be tween" the plungers, and a cross. member carried by the screw.and adapted to engage to engage th'epipes 1 6. In a centering clamp, the combination off an annular frame, a: pair of plungers. mounted therein movably toward and I from the two plungers to force the same inwardly,

the center of the frame, said 'plungers-h avingnotches facingeach other, a cross-mem benoccupyirrg' said notches, and'means for forcing said crossmemberinwardly.

It a centeringclamp, the combination ofan'annular fr ame apair of longitudinally aligned radial plungers slidably, mounted therein, said plungers having notches beyond 'the frame facing each other, a screw mounted inltlfe frame between the plungers, and. a cross member occupying; said notches and 5 adapted to be forced in. ward by the screw.

8. Iii a clamp, for a pipeworking tool, the combination of "an annularframe, a pairof plungers radially mountedthereinin longitudi'nal alignment, each plunger extending beyond the outside ofithe.frameqand'there. having-a notch. facing ,th'eother plunger, a. disk occupying the two notches and having a central hole, and a cap. screw passing through the disk and threaded into. the. frame, and having a head bearing against the outer face of the disk- I 9". In a centering clamp, the combination.

of an annular frame adapted'to surround'a 13 pipe and having three bosses formed on the of the annular frame for coac'ting with the exterior of the frame, a pair of clamping faces of the respective bosses to indicate plungers in longitudinal alignment radially the position of the clamping units. 7 10 mounted in each of the bosses and slidable In testimony whereof, I hereunto afiix my 5 therethrough, a screw device for forcing in signature.

each pair of plungers as a unit, and marks on each plunger adjacent the exposed end VERNON T.- SPRAGUE. 

